Brake for a die sinking machine



June 6, 1939.

J. M. RUSNAK BRAKE FOR A DIE SINKING MACHINE Filed Oct. 12, 1937 5 Sheets-Sheet l Ill INVENTOR.

B v JWZ June 6, 1939. J N K 2,161,683

BRAKE FOR A DIE SINKING MACHINE Filed Oct. 12, 1937 5 Sheets-Sheet 3 $612M FUSDBK June 6, 1939. J. M. RUSNAK BRAKE FOR A DIE SINKING' MACHINE 5 Sheets-Sheet 4 INVENTOR. ifzhmusnak B 1/ W A TTORN Y Nw M mm r E I \n 7 V AM u V n NR W m 1 m 3 m a T s &

June 6, 1939- J. M. RUSNAK 2,161,683

BRAKE FOR A DIE SINKING MACH INE Filedpct. 12, 1937 5 Sheets-Sheet 5 Patented June 6, 1939 UNITED STATES PATENT ornce to Niles-Bement-Pond Company, Conn., a corporation of New Jersey Hartford,

Application October 12, 1937, Serial No. 168,634

6 Claims.

This invention relates to die sinking machines and particularly to a die sinking machine of the type having means for actuating the cutter in an arcuate path of different predetermined radii.

Another object of the invention is to provide an improved braking means for the spindle which will apply a predetermined braking effect upon a driving member for the spindle and independently of the force exerted by the operator upon a hand operating lever.

And another object of the invention is that this braking means is interlocked with the circuit oi the motor for the cutter rotating spindle to open the circuit when the brake is being applied.

, The features of construction forming the present invention constitute improvements upon the die sinking machine described and claimed in the patent to Bayrer 1,354,942 granted October 5, 1920.

With the above and other objects in View, the invention may include the features of construction and operation set forth in the following specification and illustrated in the accompanying drawings.

In the accompanying drawings annexed hereto and forming a part of this specification, I have shown the invention embodied in a motor driven die sinking machine of the vertical spindle universal type, but it will be understood that some of the features of the invention can be embodied in other machine tools and that the drawings are not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawings:

Figure 1 is a complete side elevation of a die sinking machine in which the present invention is incorporated.

Fig. 2 is a vertical sectional view taken centrally through the tool spindle and showing a part of the cutter supporting and moving head.

Fig. 3 is a vertical sectional view showing the remainder of the cutter Supporting and moving head and the driving motor for the tool spindle.

Fig. 4 is a horizontal sectional view taken centrally through the operating eccentrics for the movable head for the cutter.

Fig. 5 is a plan view of the brake operating mechanism for the tool rotating spindle, and

Fig. 6 is a central vertical section taken on the plane of line 6-6 of Fig. 5.

In the above-mentioned drawings there has been shown but one embodiment of the invention which is now deemed preferable, but it is to be understood that changes and modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

Briefly and in its broadest aspect, the invention may include the following principal parts: First, a base having a column portion; second, a work supporting table adjustable vertically and horizontally to different operative positions on said column; third, a head slidably supported within a fixed upper part of the base secured to the column and movable in a Vertical plane in circular paths of different radii; fourth, a cutter spindle and supporting sleeve vertically disposed within the movable head and axially adjustable toward and from the table; fifth, a motor mounted on the movable head for rotating the spindle within its sleeve in any adjusted position thereof; sixth, a brake movable into a position against a driving pulley for said spindle; seventh, spaced adjustable eccentrics supported within the upper fixed portion of said base for moving the head in closed paths while maintaining the axis of the cutter spindle at all times vertical; eighth, means to simultaneously adjust the eccentricity 25 of said eccentrics; ninth, means to simultaneously rotate the eccentrics in any adjustable position so that a cutter in said spindle may be moved in arcuate paths of any predetermined radii; tenth, a cylindrical bearing formed in the movable head for engagement with one of said eccentrics; and eleventh, an arcuate bearing member partially engaging the other of said eccentrics and supported adjustably within the head for limited free angular and linear movements in any direction.

Referring more in detail to the figures of the the drawings, I provide a base II] having a column portion II on which is adjustably mounted for vertical movement a work supporting bracket or knee I2. On the upper horizontal surface of this bracket or knee I2 is slidably mounted a saddle i3. carrying a work supporting table I4 movable transversely thereon. A work piece W being operated on may be clamped in position on this table I3. The above described work supporting and positioning means are or may be those usually forming parts of a standard die sinking machine and may be adjusted by means of hand wheels I5; I6 and Il respectively for operating the knee I2, saddle I3 and table I4.

The base It at the upper end of the'column portion II is in the form of a fixed head portion I8 having two spaced parallel side surfaces I9 between which is movably mounted a cutter supporting head presently to be more fully described. Within this movable head 20 is a'vertically disposed cutter spindle 2| mounted adjacent one end. Preferably and as shown in' the figures, this spindle 2| is rotatable within a vertically adjustable sleeve 22 so that. the axial position of the spindle 2| may-be widely adjusted toward and from the table l4; A cutter or tool may be clamped by any usualv means to the lower end 'of the spindle 2|. effect vertical movements of the sleeve 22 and cutter spindle 2|, there is provided .a vertical= screw 24 engaging a nut 25 secured to an intermediate portion of the sleeve '22Jso. thatby rotation of this screw-.24 by' any suitable'means (not shown) the sleeve 22 and spindle 2| may be movedvertically up or down.

At the upper end of the cutter spindle 2.|=are--- provided longitudinal splines 26 extending within a compound'gear member. 2T; there preferably being asplined collar-28 directly surrounding and 'fitting' the: spline portion 26-of 1 the spindle 2| .and to which the-gears. :21 may be keyed. The collar 28 is mounted upon suitable anti-friction bearings-29"mounted within the movable head 20 so that-thespindle 2| in any vertical position maybe rotated by rotating the collar 28 and gears 21; Engageable with. the gears 21 upon the 'collaror sleeve 28 are gears 30. slidably V mounted uponan intermediate shaft 3| either 20-:is'vertically mounted a;.driving motor 33, this 7 head by meanseta-suitable.horizontal guideway preferably being. directlysecured to. a slidably mounted bracket 34 adjustal; le-. upon the movable 35. The bracket 34:may be held in adjusted. posi-.. tion :by i means of: a transverse. clamping. or .locking.- screw. 36:-

:conveniencesin adjusting. the

bracket. steward: and zfrom-ethe spindle driving pulleyi32 .adj.usting..screws..31:are;provided per- 1 cutterspindles2il.mayberotated at fourdifierent mitting accurate adiustment of the bracket, .34

and motor13.3..foi: the particular-belts. being used. L'I'he. motor :shaft .35.at its. upper ,end ,is provided .Witlrapulley 40 connected by. the belts 38;:to. -the- -pulleyz32z. upon the. intermediate shaft 31. From .the abovezdes'cribed vconstruction the rotative speeds for each speed ofathemotor 33. .ln order to;effect;limited braking, action upon the-cutterrotatingppulley 32;.when it is desired aibrake shoe. 4|loflarcuatelform and-mo-vable tostopj rotationpohthis spindle, there is provided toaposition'.to. bear1upon the drivinggpul-ley 32 'withinone of-Jits.belt;sheaves ,asshown. This.

brake; shoe 4 .is. secured. rigidly to a member 42 in: theformofa; generally-rectangular block slidably mounted within the movable head 20 and in itslreleased positionyisforced away from the pulley g by means of light springs 43 surrounding headed-rods1-44securedto the=brake shoe member 42 and having their springs bearingagainst abut? ments formedon the movablehead20. As. shown in Fig; 5; the ibrakessh'oe; member; 4215; .slidably mountedwithin 21a recess formed. horizontally within: the .movable.;head ..20 and extending/lon gitudinally therein To.retain-:;the brake shoe 4| In order to. r

45 is secured to the head 2|lclosely adjacent the Walls of the recess. The brake shoe therefore While normally retracted from the pulley 32 by its springs 43 may be moved toward and into 7 and member 42 slidably in position a cover plate contact with the pulley by moving the member 42.

.Within the brake shoe member 42 and extend-- ing from its end remote from the pulley 32 is slidablymountedan actuating member 46 which,

as shown in'Fig. 6, has a small flange at its in- .ner end and is enclosed by an adjusting screw "threaded into member 42. Interposed between the innerrendof the actuating member 46 and themember 42 is aheavy coil compressive spring 48'. From the-.aboveit will be seen that pressure exertediagainst the actuating member 46' will cause the spring 48 within the brake shoe member -42 'to be compressed beyond its initial load which willtherefore force the brake shoe 4| toward and into contact with the surface of the pulley'32. In.:itsoppositevposition theactuating againstthe inner face of the adjusting screw 41 which limits outward movement and extension of the *spring 48.. Toforce the actuating member 46 .in adirectiontoiorce the brake shoe 4| against the pulley 3.2 there is provided an adjust-Q able. screw 49.1ongitudinally threaded into and movable with the actuating member 45 .having a head 50 upon itsouter end. Preferably a locking. nut 5| is;.provided on the screw 49 to main-' 'tain adjustments. of the screw. The desired movement of1shoe4| :can be obtained byadjust ing the: screw 49 relative to the actuating member and by oscillating a cam 52. p

Adaptedlto engage against the outer face of this head. is ,a portion of the rotatably mounted cam .or memberv 52 having cut-away; portions as shown .inFig. 6, one ofwhich engages the head 50. This cam 52 is mounted upon an intermediate portion of aatransversely extending, shaft? 53.mo'untedqior oscillatory movements within the V movable .head 20. By oscillation of this shaft 53 i130 :diiferent' angular: positions, the cam. 52. inv

one position will force the brake member 42 to.- Ward-the pulley 32 and in another oscillated posi- .member.46- -will haveits inner flange end bearing tion will,;permit outward movement of theshoe 7 4| and member 42 by the'light springs 43 referred v tozabove. V p 7 Inorder to effectioscillation ofthe'cam' 52 a short-lever 54---is keyedlto one end of theshaft 53, there being va reach arm- 55 extending for- V Wardly-from-lever 54 and engaging the upper end of an. intermediately p-ivotedhand lever 56.. In one position,- therefore, of the lever 56. the brake 4| will be released and in another position the brake will be forced tightly against the pulley- 32 toefifect a ,firm. braking efiectupon the pulley andspindle-2I. The .pressure-ofthe brake shoe 4| against the pulley 32 will be wholly determined by the amount of compression of the operator,- to thehand lever .56; f

Mounted adjacent the shaft 53 will be affected by the pressure applied 1 by the stoppingthe spindle rotating motor33. This ,spring;48 within the-member 42 andin noway on whicnftii cam .52 is mounted is acswitch 51, this switch it being in: the control circuitifor startingand switch 51 is of thebutton type having .a bridge 7 member- 58 movable to circuit opening and .closing positions relative to, the switch contacts... In

the depressed position: of thebutton. 59 the switch 51 will be open and in the normal or extended position of thebuttontheswitch will beclosed. J

.Movable against the button59a is. one end :of a V small bar or rod 66, the opposite end of which is pointed and engaging the periphery of a collar 6| on the shaft 53. In the oscillated position of the shaft 53 which releases the brake 4| the bar 66 enter a V notch in the collar 6| and thus permits the button 59 of the switch 51 to be extended by a spring within the switch to move the bridge member 59 into a position to close its circuit. In the other oscillated position of the shaft 53 in which position the brake 4| is being applied to the pulley 32 the bar 66 rides out of the notch provided in the collar 6| which depresses the button 59 of the switch 61 and thus opens the control circuit for the spindle driving motor 33. Motor 33 therefore cannot be started while the brake 4| is being applied.

The movable head 26 within which is mounted the cutter spindle 2| and sleeve 22 is mounted upon eccentric sleeves 62 and 63, one of which is shown in Fig. 2, and the other in Fig. 3. These eccentric sleeves 62 and 63 are similar to each other and form parts of eccentrics of the compound type, there being two eccentrics, one within the other relatively adjustable to vary the eccentricity of the eccentric sleeve relative to the shaft 64 on which it is mounted. The construction of these eccentrics is similar and their means for adjusting their eccentricity is similar so that but one of these eccentrics will require description. As will be seen in Figs. 2, 3 and 4, the sleeves are mounted upon inner eccentric surfaces 66 formed integrally with the shafts 64.

Preferably these inner eccentrics 66 formed upon the shafts 64 have bearing portions or journals 61 on opposite sides of the eccentric surfaces 66 and are supported in fixed position for rotation within the fixed head portion I8 of the base, there being a cover plate 68 rigidly fastened to the base and forming one side of the fixed head |8 in order to permit assembly of these eccentrics. Surrounding each integral or inner eccentric 66 is the eccentric sleeve 62 and 63. These sleeves have internal gear teeth 69 formed therein and meshing with the teeth of a pinion 16 upon a shaft 1| extending through the inner eccentrics 66 coaxially of their journal portions 61.

The eccentrics 62 and 63 shown in Figs. 2 and 3 are rotatable simultaneously by means of gears secured to one end of their supporting shafts 64, these gears 12 meshing with a common intermediate gear 13. The intermediate gear 13 for driving the eccentrics 62 and 63 is mounted rotatably upon a stud 14 fixed within the cover plate 68 and provided with a worm wheel keyed thereto and meshing with a horizontally disposed Worm 16. The worm 16 is supported horizontally within the cover plate 68 so that rotation will slowly rotate the eccentrics simultaneously and will therefore actuate the movable spindle head 26 in a closed arcuate path. The worm 16 by means of which the eccentrics are simultaneously rotated may be manually rotated by a hand wheel 11 on the forward end of its shaft 18. Also if desired a small motor 19 may be mounted on a portion of the fixed head drivingly connected to the worm shaft 18 through a suitable telescoping and jointed connection with the shaft 18.

In order to vary the radius of the path of movement of the movable head 26 the shafts 1| on which the adjusting pinions 16 are mounted have at their outer ends driving gears 86 of the same diameter and number of teeth as the gears 12 for the inner eccentrics 66. These latter gears 86 are in mesh with a common intermediate gear 8| so that by rotation of this intermediate gear 8| while the worm wheel 15 and eccentric driving gears 12 are maintained relatively fixed the radius of movement of the cutter head may be varied.

To effect this adjustment, a worm wheel 82 is keyed so as to be rotatable with the intermediate gear 8|. This worm wheel 82 may be mounted on a sleeve formed on worm wheel 15 and meshes with a worm 83 housed within and having its shaft supported within a member 84 rotatable with the worm wheel 15 for the eccentric driving gears 12. By means of a hand wheel 85 on the outer end of a short shaft connected drivingly with the worm 83 the eccentric sleeves 62 and 63 may be widely varied relative to their axes of rotation on the inner eccentrics.

The path of movement of the head 26 and spindle 2| may be widely varied by rotation of wheel 85 and during operation of the spindle the member 84 within which the worm 83 is mounted rotates about the axis of stud 14 with rotation of gear 15. In universal die sinkers as at present made the mountings for eccentrics such as shown at 62 and 63 have each been fixed and similar one to another. It has been found, however, that due to unavoidable inaccuracies in manufacture or inaccurate alignment and adjustment of the parts supporting the movable head '26 that a cramping action may occur in the bearings which prevents smooth and easy rotation of the eccentric driving mechanism to move the tool in an arcuate path. It is therefore a feature of the present invention to eliminate the possibility of the eccentrics 62 and 63 upon which the movable head 26 is supported becoming cramped by lack of accurate adjustment or misalignment or unavoidable errors in manufacture. As shown in Fig. 2, the eccentric sleeve 62 adjacent the cutter spindle 2| is directly mounted within a fixed cylindrical surface formed directly within the movable head 26. This front eccentric, therefore, accurately controls the vertical and lateral positions of the cutter head 26 at all times. The rear eccentric 63 more remote from the cutter spindle 2| is mounted within the head 26 by a special and improved bearing member and support shown most clearly in Fig. 3.

It will be seen by reference to Fig. 3 that the movable head 26 is cut away to form an enlarged recess surrounding the sleeve 63 for the rear eccentric, there being a small arcuate surface 86 integral with the movable head 26 and bearing against the lowermost portion of sleeve 63. The upper surface of the eccentric sleeve 63 upon which the weight of the movable head 26 is principally supported bears against an inserted arcuate member 81 which is so mounted Within the head 26 that it is free to adjust itself within limited distances either laterally or by tilting or by movement angularly about a vertical axis.

Preferably this arcuate bearing member 81 may have a central recess 88 within its upper portion within which may loosely fit a vertically disposed stud 89 adjustably threaded within the movable head 26. A ball 96 of relatively large diameter inserted within the recess 88 and within the recessed lower end of the stud 89 is positioned between bearing plates 9|, one plate being mounted in the arcuate member 81 and the other directly thereabove in the stud 89. With this construction and with the ball 96 forming the weight supporting member, the arcuate membe 81 is free to tilt slightly about a horizontal axis or about a vertical axis or may move slightly laterally within the recess 88. By means of this freedom of movement cramping action between the eccentric sleeves Stand '63 together with the-inner eccentricsGBIY In lieu of the motor 19 for actuating-the tool 21 in its arcuate path the hand Wheel ll may be rotated l What I claim-is: V 1. A spindle brake for machine tools com-' j prising incombination, a spindle, a driving pulley V '7 therefor, a brake shoe movable into and out of contact with'said pulley, a cam adjacent said shoe,-.means to oscillate said cam, an actuating member for said shoe;'and a spring housed within said shoe and disposed bet'ween said actuating member and cam, whereby oscillation of said cam in one direction com'pressessaid spring and forces said .shoe against said pulley."

2. A spindle brake for: machine tools comprisingin combination, a spindle, a driving pulley therefor, a-brake shoe movable into and out of contact withsaid pulley, a cam adjacent said 7 7 shoe, :means to oscillate saidcam, an actuating member for said shoe, aspring-h'oused within said shoe and disposed between said'actuating member and cam, and means within said shoe whereby the compression of said' spring may be varied.

3. A spindle brake formachine tools comprising in combination, a spindle, a driving pulley therefor, a brake shoe movable into and outof contact with'said pulley, a cam adjacent said shoe, means to oscillate said cam, anv actuating -member-for said shoe movedby oscillation of said cam, a com- I pressive'spring housed within said shoe and disposed between said actuating member and cam,

andrmeans within said shoe to adjust the com- I pression of said spring,- whereby oscillation of said cam in'oone direction will force said shoe against said pulley with-a force determined by the adjustment of said spring.

4. A spindle brake formachine tools comprising in combination, a spindle, a driving 'pulley therefor; a brake shoe movable into and out of contact with said pulley, an actuating member for said shoe housed within said shoe, a spring within said shoe and forcing said actuating member away from saidshoe, means limiting the movementiot said actuating member away from said shoe, and a' cam oscillation of which forces said member toward said shoe and said shoe resiliently'against said pulley. V i

' 5. A spindle brake for machine tools comprising in combination, aspindle, a driving pulley therefor; a brake shoe movable intoand out of contact with said'pulley, an actuating member forsaid shoe-housed within saidshoe, a spring:

' within'said shoe and forcing saidactuating memberaway from said I shoe, means limiting: the movement of said member away from saidshoe,

a cam oscillation of which forces said member toward. said shoe and said shoe resilientlyagainst said pulley, and means normally holding said shoe awayffrom said pulley.

6. A spindle brake for-machine tools comprising in combination, a spindle, a driving pulley therefor, a brake shoe movable into and out of contact therewith, a cam adjacent said shoe,

means to oscillate said cam, an actuating member forisaid shoe movable by said cam, aspiring-dis posed between said actuating member-and shoe whereby operation'of said actuating member by said'cam resiliently forces said shoeagainst said pulley, and/means to vary the force exerted a a t Said p ey b-ysaid shoe'when said cam: is oscillated,

- 'JOHN M. RUSN'AK. 

